1. Field of the Invention
This invention relates to security tags used in theft prevention, and more particularly to mechanisms for attachment of security tags to items to be protected or identified.
2. Description of the Related Art
Theft deterrence is presently accomplished in several ways. Items to be protected can simply be locked up. However, in sales environments, placing merchandise under lock and key virtually eliminates impulse purchasing and generally reduces sales volume. Benefit denial is another technique utilized in which the benefit of the use of stolen articles is removed to eliminate the motivation for taking the articles. Benefit denial includes the use of ink tags that are attached to the articles to be protected. When an attempt is made to remove the ink tags from protected goods, the ink tags rupture spilling the contents, which is typically permanent ink, over the article and the thief. Another technique to deter theft is to attach tags that are detectable by electronic article surveillance systems to articles to be protected.
Electronic article surveillance (EAS) systems are well known in the art and are used for inventory control, identification, and to prevent theft and other unauthorized removal of articles from a preselected area. Typically, such systems include at least one transmitter and at least one receiver that provide one or more surveillance zones that articles must traverse to be removed from the preselected area.
An EAS security tag is affixed to each article to be protected. The EAS tag includes a marker or sensor adapted to interact with a signal transmitted by the system transmitter in the surveillance zone. The interaction of the marker or sensor causes a further signal to be established in the surveillance zone that is detected by the system receiver. Accordingly, upon movement of a tagged article through the surveillance zone, a signal will be generated and received by the system receiver identifying the presence of the tagged article in the zone.
Certain types of EAS tags have been designed to be reusable, and thus include releasable attachment devices for affixing the tags to the articles to be protected. The attachment devices are designed to be releasable only by authorized personnel, and typically require the use of an associated special tool or detaching mechanism.
A reusable EAS tag that is particularly reliable and is in wide usage for theft deterrence is illustrated in U.S. Pat. No. 5,426,419, to Nguyen et al., the disclosure of which is incorporated herein by reference.
Referring to FIGS. 1 and 2, one embodiment of an EAS tag 1 includes a tag body 2 and an attachment mechanism comprising a tack assembly 4 having a tack head 40 and an elongated tack body 41. EAS tag 1 and tack assembly 4 are fully disclosed in, and illustrated in FIGS. 1 and 6A of, the '419 patent. For convenience, relevant portions of FIGS. 1 and 6A are reproduced herein as FIGS. 1 and 2, respectively.
The tack body 41 is receivable within a first opening in the tag body 2. A receiving and clutching means within the tag body 2 receives and clutches one of the slots or grooves 42 in tack body 41, preventing withdrawal of the tack body 41 from the tag body 2. A second opening 9 in the tag body 2 includes an arcuate channel that permits an arcuate probe to be guided into a means for releasing the clutching means, thereby allowing withdrawal of the tack body 41 and separation of the tack assembly 4 from the tag 1.
To affix the tag 1 to an article 51 to be protected, the tack body 41 can be pushed through a portion of the article 51 and inserted into the first opening in the tag body 2, where it is clutched by the clutching means. The tack body 41 includes a pointed end 43 that facilitates pushing tack body 41 through various articles 51. For some applications, it is desired that the tack body 41 should not, or cannot be passed through a portion of the article.
For example, when an EAS tag is attached to a shoe, the tack body 41 can be passed through one of the shoe's lace eyelets to secure the tag 1 to the shoe. This practice is fine for some shoe types. However, the tag/tack head often covers the eyelet interfering with the lacing process and/or may put an undesired indentation into the shoe leather.
In addition, articles such as briefcases, luggage, power and hand tools, sporting goods, and many other hard and soft goods cannot be properly tagged because the tack body cannot be passed through a portion of the article.
Referring to FIG. 3, for those applications where the tack body is not passed through a portion of the article, a wire lanyard 3 having a loop 6 at each end can be wrapped around, or passed through a suitable opening in the article to be protected. The wire lanyard 3 can be secured to the tag by passing the tack body 41 through one or both of the end loops 6, and inserting the tack body 41 into the first opening in the tag body 2. However, the wire end loops 6 disposed around the tack body 41 prevents the tack head 40 from resting relatively flush against the tag body 2 leaving space 7. The space 7 caused by the wire between the tack head 40 and the tag body 2 may permit an unauthorized person to apply leverage against the tack head 40 and possibly pry out the tack body 41 from the clutching means, thereby removing the tag from the article.
In applications using EAS and other tags of the type that include a tack assembly comprising a tack head and tack body as part of the attachment mechanism in which the tack head is prevented from resting properly adjacent the tag body, an improved tack attachment mechanism is needed.